| Little Folks Ventures Limited | Real estate | 2009 |
| Little Jardin Ltd | Professional & scientific | 2025 |
| Little Leaders Daycare Ltd | Education | 2013 |
| Little Maison Ltd | Real estate | 2025 |
| Little MAN Systems Ltd | Information & communication | 2003 |
| Little Nasa Limited | Health & social care | 2026 |
| Livco Group Ltd | Wholesale & retail | 2024 |
| Live Action Gaming Ltd | Arts & recreation | 2019 |
| Live LAP Timing Ltd | Wholesale & retail | 2019 |
| Live Transport Ltd | Transport & logistics | 2018 |
| Livwell Estates Ltd | Real estate | 2025 |
| LJ Fits Ltd | Wholesale & retail | 2025 |
| LJ Loaded Ltd | Information & communication | 2023 |
| LJS Electrical & Security Ltd | Construction | 2010 |
| LK Aesthetics Ltd | Other services | 2021 |
| LKW Financial Limited | Financial services | 2015 |
| Llamago Ltd | Administrative & support | 2019 |
| Lloyd & Rose Group Ltd | Administrative & support | 2024 |
| LMC Brickwork Ltd | Construction | 2018 |
| LMC Industrial Services Limited | Professional & scientific | 2024 |
| LMC Pipeworks Ltd | Manufacturing | 2014 |
| LMC Property Investments Limited | Real estate | 2025 |
| LMJ Group Limited | Financial services | 2023 |
| LMT Motorcycles Ltd | Administrative & support | 2020 |
| LMW Plumbing & Bathrooms Limited | Construction | 2023 |
| LMW Plumbing & Tiling Ltd | Construction | 2024 |
| LNC Civils Ltd | Construction | 2022 |
| Loake Brothers Holdings Limited | Financial services | 2023 |
| Loake Brothers Limited | Manufacturing | 1895 |
| Loake Consultancy Ltd | Information & communication | 2019 |
| Loake Media Limited | Arts & recreation | 2021 |
| Lobelia Cottages Management Limited | Households | 2005 |
| Local Freight Express Ltd | Transport & logistics | 2025 |
| Local Leaflet Drop Limited | Professional & scientific | 2014 |
| Local Recruitment Group Limited | Administrative & support | 2025 |
| Locally Yours Ltd | Wholesale & retail | 2025 |
| Location Repairs Services Limited | Wholesale & retail | 1998 |
| Locked Inland Ltd | Transport & logistics | 2014 |
| Lockley Holdings Limited | Financial services | 2022 |
| Loddington Coppice Equine Healthcare Ltd | Agriculture & fishing | 2020 |
| Loddington Hall Management Company Limited | Households | 1989 |
| Lodge Farm Trade Ltd | Wholesale & retail | 2025 |
| Lodge House UK Limited | Real estate | 2004 |
| Lodge Park Homes Limited | Construction | 2012 |
| LOG in to My Club Ltd | Information & communication | 2026 |
| LOG4 Ltd | Professional & scientific | 2021 |
| Logicmode Ltd | Information & communication | 2020 |
| Logistex Europe Ltd | Manufacturing | 2010 |
| Logistex Limited | Transport & logistics | 1937 |
| Logistex Trustees Limited | Administrative & support | 2018 |
| Logistics Consultancy Limited | Professional & scientific | 2018 |
| Lollyrocket Limited | Manufacturing | 2018 |
| London Pace Limited | Administrative & support | 2013 |
| London Road Store Limited | Wholesale & retail | 2025 |
| London Trim Ltd | Other services | 2026 |
| Lone Wolves Limited | Financial services | 2022 |
| Long Swallow Tattoo Club Limited | Other services | 2023 |
| Longcroft & Gayton Limited | Professional & scientific | 2026 |
| Longfellow Management Limited | Professional & scientific | 2019 |
| Longfield Solutions Limited | Administrative & support | 1999 |
| Longterm Flavell Investments Ltd | Real estate | 2022 |
| Loomi Healthtech Ltd | Information & communication | 2026 |
| Loop Logistics Solutions Limited | Transport & logistics | 2012 |
| Louise Wright Theatre School Limited | Arts & recreation | 2020 |
| Loundsley (East Midlands) Development Limited | Construction | 2020 |
| Lourett Developments Limited | Real estate | 2018 |
| Love Brickwork Limited | Administrative & support | 2014 |
| Love Financial Services Ltd | Financial services | 2013 |
| Love Food JM Limited | Hospitality | 2014 |
| Love in Bloom Ltd | Wholesale & retail | 2019 |
| Love Kettering CIC | Administrative & support | 2024 |
| Love Soapy Ltd | Wholesale & retail | 2020 |
| Loveday Commercials Ltd | Real estate | 2011 |
| Loveridge Machinery Services Limited | Manufacturing | 2005 |
| Lovevics Catering Limited | Hospitality | 2019 |
| LOW Carbon Energy Assessors (Lcea) Limited | Extraterritorial | 2008 |
| Lower Street Primary Care Centre Limited | Health & social care | 2006 |
| Lowick Manor Farms Limited | Agriculture & fishing | 1960 |
| Lowick Vineyard Limited | Agriculture & fishing | 2015 |
| LP Property Limited | Real estate | 2016 |
| LPC Electical Ltd | Construction | 2025 |
| Lpms Burnham Ltd | Real estate | 2023 |
| Lpms Group Ltd | Real estate | 2023 |
| Lram Limited | Other services | 2009 |
| Lsavickas Transport Ltd | Transport & logistics | 2016 |
| LT Electrical (Northamptonshire) Limited | Construction | 2022 |
| LTA Mortgages Ltd | Financial services | 2018 |
| Lucas Lettings Limited | Real estate | 2009 |
| Ludi Projects Ltd | Construction | 2022 |
| Ludlam Estates Ltd | Real estate | 2025 |
| Luel Studios Ltd | Arts & recreation | 2024 |
| Luistransport Ltd | Transport & logistics | 2023 |
| LUK2000 Ltd | Transport & logistics | 2011 |
| Luke Vision Ltd | Wholesale & retail | 2024 |
| Lukrative Consulting Ltd | Professional & scientific | 2023 |
| Luli Crafts Ltd | Wholesale & retail | 2020 |
| Luma Fixings Ltd | Wholesale & retail | 2018 |
| Lumi SKN Ltd | Wholesale & retail | 2020 |
| Lumoravr Ltd | Information & communication | 2023 |
| Lunabio Ltd | Manufacturing | 2024 |